1. Field of the Invention
The present invention relates in general to the field of computers and similar technologies, and in particular to software utilized in this field. Still more particularly, it relates to a method, system and computer-usable medium for optimizing a Partitioned Data Set Extended (PDSE) directory.
2. Description of the Related Art
When a data set is allocated, a certain amount of space is reserved in units of blocks, tracks, cylinders, etc., on a storage disk or a storage device. A Partitioned Data Set Extended (PDSE) adds a layer of organization to the data set and includes a directory and one or more members. The directory uses a b-tree structure to reduce member search times. However, the b-tree directory structure does not take into account the realities of I/O operations and caching as implemented by a PDSE. As a result, all initial member opens have an equal chance of either having needed directory pages in cache or having to perform I/O operations to read the pages from a Direct Access Storage Device (DASD). In addition, the b-tree directory structure does not account for member usage, treating all members equally whether they have one access a month or one million.